Scalar Data Types

Built-in scalar data types.

Description

These are the data types available in the OpenCL C programming language used to create
kernels that are executed on OpenCL device(s). The OpenCL C programming language (also
referred to as OpenCL C) is based on the ISO/IEC 9899:1999 C language specification
(a.k.a. C99 specification) with specific extensions and restrictions. Please refer
to the ISO/IEC 9899:1999 specification for a detailed description of the language
grammar. This section describes modifications and restrictions to ISO/IEC 9899:1999
supported in OpenCL C.

Most built-in scalar data types are also declared as appropriate types in the OpenCL API
(and header files) that can be used by an application. The following table describes
the built-in scalar data type in the OpenCL C programming language and the corresponding
data type available to the application:

Type in OpenCL C Language

Description

API type for application

bool

A conditional data type which is either true or
false. The value true expands
to the integer constant 1 and the value false
expands to the integer constant 0. When any scalar value is converted
to bool, the result is 0 if the value compares equal to 0; otherwise,
the result is 1.

n/a

char

A signed two's complement 8-bit integer.

cl_char

unsigned char,uchar

An unsigned 8-bit integer.

cl_uchar

short

A signed two's complement 16-bit integer.

cl_short

unsigned short,ushort

An unsigned 16-bit integer.

cl_ushort

int

A signed two's complement 32-bit integer.

cl_int

unsigned int,uint

An unsigned 32-bit integer.

cl_uint

long

A signed two's complement 64-bit integer.

cl_long

unsigned long,ulong

An unsigned 64-bit integer.

cl_ulong

float

A 32-bit floating point. The float data type must conform to the
IEEE 754 single precision storage format.

cl_float

double

A 64-bit floating point. The double data type must conform to the
IEEE 754 double precision storage format. The double scalar
type is an optional type that is supported if CL_DEVICE_DOUBLE_FP_CONFIG
for a device is not zero. See the table for param_name for
clGetDeviceInfo
for details.

The unsigned integer type of the result of the sizeof
operator. This is a 32-bit unsigned integer if CL_DEVICE_ADDRESS_BITS
defined in clGetDeviceInfo
is 32-bits and is a 64-bit unsigned integer if CL_DEVICE_ADDRESS_BITS
is 64-bits.

n/a

ptrdiff_t

A signed integer type that is the result of subtracting two pointers.
This is a 32-bit signed integer if CL_DEVICE_ADDRESS_BITS defined in
clGetDeviceInfo
is 32-bits and is a 64-bit signed integer if CL_DEVICE_ADDRESS_BITS
is 64-bits.

n/a

intptr_t

A signed integer type with the property that any valid pointer to
void can be converted to this type, then converted back
to pointer to void, and the result will compare equal
to the original pointer. This is a 32-bit signed integer if
CL_DEVICE_ADDRESS_BITS defined in table 4.3 is
32-bits and is a 64-bit signed integer if CL_DEVICE_ADDRESS_BITS
is 64-bits.

n/a

uintptr_t

An unsigned integer type with the property that any valid pointer to
void can be converted to this type, then converted back
to pointer to void, and the result will compare equal to
the original pointer. This is a 32-bit signed integer if
CL_DEVICE_ADDRESS_BITS defined in table 4.3 is
32-bits and is a 64-bit signed integer if CL_DEVICE_ADDRESS_BITS
is 64-bits.

n/a

void

The void type comprises an empty set of values; it is an
incomplete type that cannot be completed.

void

Optional Half Floating Point

The half floating-point is supported as an optional
extension. An application that wants to use half
and halfn will need to include the
#pragma OPENCL EXTENSION cl_khr_fp16
: enable directive. This will extended the list of
built-in vector and scalar data types to include the following:

Type in OpenCL Language

Description

API type for application

half2

A 2-component half-precision floating-point vector.

cl_half2

half3

A 3-component half-precision floating-point vector.

cl_half3

half4

A 4-component half-precision floating-point vector.

cl_half4

half8

An 8-component half-precision floating-point vector.

cl_half8

half16

A 16-component half-precision floating-point vector.

cl_half16

The relational, equality, logical and logical unary operators can be used with
half scalar and halfn
vector types and shall produce a scalar int and vector
shortn result respectively.

The OpenCL compiler accepts an h and H suffix on floating point literals, indicating
the literal is typed as a half.